The knee and ankle joints of a person's leg and, to some extent, the person's hip, and the, muscles and tendons associated therewith require a certain amount of exercise, particularly in those instances in which the person is either too infirm to walk or has been injured in such manner as to make walking either undesirable or impractical. Nevertheless, exercise is necessary to maintain functionality of the ankle and knee joints, the muscles and tendons associated therewith, and to some extent the upper leg and hip while the person is seated.